Obvious I know, but it’s a fundamental rule so bears repeating. Don’t just read in your genre either, and read stuff where you envy the writer’s talent so much it makes you want to pour coffee all over your laptop and just go and work at Tescos. If you just pick up prose so you can say, ‘I can write better than that – they should publish ME’, you’re not going to get any better as a writer and that should be the goal every day. Get better. Read things you love and ask ‘how did they DO that?’
I remember when I had finished my first draft of Instruments reading Ingenious Pain by Andrew Miller and having a big coffee / Tesco moment. I felt totally deflated by how good his prose was, and how brilliantly he had evoked the period. Then I thought well I’m not going to become a better writer sulking. I’ll probably never write a paragraph as good as the opening of that book, but I’ll only improve as a writer if I keep trying. ‘…a man’s reach should exceed his grasp, Or what’s a heaven for?’ Don’t think I thought that exactly, just ‘bugger it then, back to the laptop,’ but the principle is the same.